These are secrets moves which I discovered, while playing Tomb Raider One, Two and Three. They work on PC and Playstation, in all of the Tomb Raider Games. I've checked all of the instruction booklets and they aren't printed in any.

Dive: If you have Tomb Raider One and you've watched the demos at the beginning , you'll see Lara dive off a cliff into a Pool of water. To do this just jump as normal, but just as you've left the ledge, box, cliff, etc. press and hold the Walk button. If executed properly you've should've made a groovy dive. 

Hand Stand Thing ma jig: Ok all you have to do is vault or jump up onto an object as usual. Now to do this move it has to be one of those jumps where she is holding on about to pull herself up, while she is clinging to the ledge press and hold the walk button, you should've now executed a cool hand stand ma jig.